Substitute Breno Lopes scored deep into stoppage time as Palmeiras won its second Copa Libertadores title with a 1-0 victory against Santos in an all-Brazilian final.
It was the first South American title for the Sao Paulo club since 1999.
Palmeiras won with its first shot on goal in a match that disappointed any neutral fans on Saturday.
"I could never dream this could happen in my life, just the other day I was playing in the second division," Lopes said.
A Portuguese coach won the prestigious South American title for the second straight year. Palmeiras' Abel Ferreira, who took over in November, follows the footsteps of Jorge Jesus, who won the title last year with Flamengo.
The Copa Libertadores title was also the first title for 42-year-old Ferreira as a manager.
The two Sao Paulo teams were bitter rivals in the 1960s, and some fans of both sides travelled to Rio de Janeiro to cheer from outside the Maracana stadium despite the coronavirus threat.
Little-known Lopes joined Palmeiras in November, coming from second division team Juventude. Ferreira brought him on at 84 minutes, replacing midfielder Gabriel Menino and intending him to be a target man for crosses.
The plan worked perfectly nine minutes into stoppage time. Rony crossed from the right and found Lopes, who headed the ball to the left of Santos goalkeeper John.
Although fans weren't allowed, the final did have 4,000 invited guests watching the match, without too much apparent regard for social distancing. Some of them did not wear protective masks. All took COVID-19 tests to be able to attend, the South American soccer confederation said.